In known such devices, a tape holding case holds a supply of image receiving tape and a supply of an image transfer ribbon the image receiving tape and the transfer ribbon being passed in overlap through a printing zone of the printing device. In our earlier copending U.S. application Ser. No. 08/069,256, there is described a different type of thermal printing device which receives two separate tape holding cases, one holding a supply of image receiving tape and the other holding a supply of an image transfer ribbon. The image receiving tape and the transfer ribbon must again be located in overlap through a printing zone of the printing device. The tape holding case or cassette which holds the supply of image receiving tape has a recess for accommodating a platen of the printer, the image receiving tape being guided across that recess by guide features of the cassette. The tape holding case or cassette holding a supply of image transfer ribbon has a recess for accommodating a printhead of the printing device, the image transfer ribbon being guided across that recess by guide features of the cassette. The platen and printhead cooperate to define a print zone. In normal operation of the printing device, the image receiving tape cassette is located in a cassette receiving bay of the printing device with the image receiving tape guided across the platen receiving recess. The image transfer ribbon cassette is likewise received in the cassette receiving bay of the printing device with the image transfer ribbon guided across the printhead receiving recess in overlap with the image receiving tape. The cassettes can be separately and independently removed and replaced in the printing device.
The printhead is movable between an operative position in which it holds the image transfer ribbon and image receiving tape against the platen for printing and an inoperative position in which it is spaced from the platen to enable the cassettes to be released. A difficulty can arise in that, when the printhead is returned from its operative position to its inoperative position, the image transfer ribbon may retain its original shape since it has insufficient resilience to be drawn back with the printhead. If this happens, there will be a loop of image transfer ribbon which will make it difficult for the image receiving tape cassette to be inserted into the printing device. The present invention seeks to overcome this problem.